FIG. 1 is a block diagram showing a configuration of a conventional payment system 1. The payment system 1 is composed of an upper terminal 11 composed of a register of a POS (Point of Sales) system or the like; and a payment terminal 12. The payment terminal 12 is composed of a terminal for user interface (UI) control 21 and a terminal SAM 22.
The terminal SAM 22 performs a payment process with an IC card (not shown), based on a service application included therein. Therefore, the terminal SAM 22 performs RF (Radio Frequency) control for communication with the IC card, and control of communication with the UI control terminal 21.
The terminal for UI control 21 performs control of communication with the terminal SAM 22 and control of communication with the upper terminal 11, in addition to control of UI devices such as a display device (not shown).
Control of communication with the terminal SAM 22 is performed according to a protocol defined by firmware of the payment terminal 12. On the other hand, control of communication with the upper terminal 11 is performed according to a protocol defined by the upper terminal 11.
As a result, for example, when the terminal SAM 22 or the upper terminal 11 is replaced with one from a different manufacturer, there is a need to readjust the communication protocol.
Patent Document 1 proposes that a relay module is provided to each client device, and the client devices communicate mutually using their relay modules, through a dedicated server arranged on the Internet.
Application of the technique of Patent Document 1 to the payment system 1 is considered.